Grinder with compensating trimming mechanism



GRINDER WITH COMPENSATING TRIMMING MECHANISM Filed March .3, 1958 July12, 1960 MENTLEY ETAL I5 Sheets-Sheet 1 INVENTORS MAX B.MENTLEY ZENONKOKORZYCKI AVID W. DANIEL ATTORNEYS July 12, 1960 Filed March 5, 1958 M.a. MENTLEY ETAL 2,944,373

GRINDER WITH COMPENSATING TRIMMING MECHANISM 3 Sheets-Sheet 2 INVENTORSMAX B.MENTLEY ZENON KOKORZYGKI BY DAVID W.DAN|EL GRINDER .WITHCOMPENSATING TRIMMING MECHANISM Filed March 5, 1958 July 12, 1960 M. B.MENTLEY ETAL 3 Sheets-Sheet 3 ana INVENTORS MAX B.MENTLEY ZENONKOKORZYCKI AVID W. DANIEL ATTORNEYS GRINDER WITH COIVIPENSATING TRINIMINMECHANISM Max B. Mentley, Zenon Kokorzycki, and David W. Daniel, all ofDetroit, Mich., assignors to National Broach & Machine Company, Detroit,Mich., a corporation of Michigan Filed Mar. 3, 1958, Ser. No. 718,768

6 Claims. (Cl. 51-5) column, an adjusting nut-mounted for-rotation in afixed position 'on a column supporting frame and selectively rotatable,a trimmer slide on said column, a nut fixed to said trimmer slide, andmeans for'selectivelyrotating said feed screw and said adjusting nut.

' Other objects and features of the invention will become apparentas-the description proceeds, especially when taken in conjunction withthe accompanying drawings, illustrating a preferred embodiment of theinvention, wherein: 2

- Figure 1 isa fragmentary elevationalview of a portion of the grinder.

' Figure 2 is a fragmentary vertical section through the mechanism shownin Figure 1 Figure 3 is a plan'view of the mechanism, partly in section.a a

Figure 4 is a composite sectional view taken in part on the line 4a4b ofFigure 2, and in part on the line 4a-4c of Figure 2.

Referring now to the drawings, the grinder comprises a frame or base 10having an upstanding hollow portion 12 in'which is received a verticallymovable column 14. At its upper end the column 14 has fixedly securedthereto a table or plate 16 having T-slots 18 in which are movablysecured the head of T-bolts 20 securing the grinder head 22 thereto.support portion 24 carrying the rotatable grinding wheel 26v which isadapted to be driven by suitable means such for example as the belts 28connecting sheaves'30 driven by a motor 32, and sheaves 34 connected tothe wheel The grinder head comprises a wheel 1 moved into accuratelypredetermined position by means of indicia indicated at 42 on a drum ordisc secured to the shaft.

Referring now more particularly to Figures 2 and 4, it will be observedthat the hollow vertically extending portion 12 of the frame. 10 isprovided with a vertically extending open side as indicated at 44. Thecolumn 14 which is vertically movable in the frame portion 12 is alsoprovided with a vertically extending opening as. indicated at 46 inFigure 4. In this figure it will be observed that sectional views on twodifferent levels have been combined to avoid unnecessary duplication inthe figures.

Rigidly secured to the front of the portion 12 of the frame 10 is ahousing 48, a connection of the housing beingindicated by the assemblyscrew 50. Within the housing 48 is a shaft 52 having a worm 54 fixedthereto and having a hand wheel 56 fixed to its outer end. Journaled tothe housing is a shaft 58 carrying a worm gear 60 which is rigidlysecured to a drive gear 6 2. The housing 48 includes an inwardlyextending portion 64 received within an inwardly shaped-portion 66 ofthe column, and the inwardly extending portion 64 supports a nut 68having a gear portion 70 in mesh with thegear Rotatably carried by thetable or plate 16 is a compound screw 72, the screw being mounted forfree rotation but being held against endwise movement. .At its lower.end the screw 72 includes a threaded. portion 74 in which the threadsare of a predetermined hand such for example as left hand. The upperportion of the screw as indicated at 76, is of the opposite hand as forexample right hand. The hand of the threaded portions is immaterialexcept that it is essential that the threaded portions be of .dilferenthand. Mounted on the column 14 in Ways indicated at 78 is a trimmerslide 88 carrying suitable trimming mechanism. The nature of the trim-.ming mechanism will of course depend upon the particu- .lar form to beimparted to the periphery of the wheel. In general, it includes apivotally mounted diamond and may include templates for. producing a,required form. The detailed construction of the trimmer is immaterial tothe present invention and the trimmer is indicated diagrammatically at82 in Figure 2.

Fixedly secured as by a pin 84 to the upper end 'of the compound screwshaft 72 is a worm gear 86 which is in mesh with a worm 88 carried by ashaft 90 extending outwardly of the column 14 where it is connected to ahand wheel 92. The shaft 90is received in suitable supporting andhousing structure 94 fixedly connected as by screws 96 to the column sothat the hand wheel 92, worm S8,v

worm gear 86, and compound screw shaft-72 all move vertical-1y when thescrew shaft is rotated relative to the stationary nut 68.

supporting spindle 3-6. When the T'bolts 20 are loosened 1 thehead .22is movable transversely or in a direction parallelto the axis of thespindle to position the; grinding wheel 26 either on-center oroff-center with respect to a work piece '(not shown) suitably mounted onthe machine. The transverse movement of the grinder head permits thewheel to be mounted off-center with respect to a gear so as to performan exceptionally eflicient gear tooth grinding operation known asoff-center grinding. It also permits the grinding wheel to be shifted toa cen- .Inasmuch as the nut 68 is connected through gearing 62' and 70and through the worm and worm gear combination 60, 54,-.it will beapparent that unless the hand wheel 561's rotated,' the nut 68 is fixedagainst rotation. Accordingly, when the hand wheel 56 is rotated,rotation is impartedtothe nut, 68. At timetheworm and worm gear 86, T88and accordingly, the compound shaft72 is thus elevated or lowered withrespect to the nut 68,

tral-ized position for trimming so that the trimmer may be fixedlymounted, and errors attributable to movement of the trimmer to differenttrimming positions are thus completely eliminated. The transverseadjustment of the head 22 is accomplished by a feed screw 38 associatedwith a nut, the feed screw being rotatable by a squared end section 40exterior of thehead. The head mayrbe thereby raising or lowering thecolumn and all mechanism connected thereto.

The trimmer slide includes a stationary nut 98 which is in threadedengagement with the upper end portion 76 of the compound screw shaft 72.It will be apparent that when the hand wheel 92 is rotated rotation isimparted V 7 directly to the compound screw shaft 72. Rotation of theassociated therewith including the column 14 and the table or plate 16.However at this time rotation of the screw shaft also results in aseparate independent and superimposed movement of the trimmer slide 80.The pitch of the threads of the upper and lower threaded portions of thecompound screw shaft 72 are equal As a result of this upward movement ofthe column 14 and hence of the grinding Wheel 26 in any amount isaccompanied by an equal upward movement of the trimmer slide. Thus forexample, if the wheel requires trimming and if the hand wheel 92 ismoved to feed the wheel 26 upwardly by .0001", thetrimmer 82 movesupwardly relative to the wheel by an equal amount and is thus positionedto remove from the periphery of the wheel an amount of stock exactlyequal to the amount by which v the wheel was fed upwardly. Thus, if itis assumed that the Work piece such as a gear, is in working positionlocate directly above the center of the wheel, it will be appreciatedthat repeated trimming of the wheel may be accomplished as desiredwithout regard to the amount of 1 stock removal, and the repositioningand trimming of the Wheel is carried out in such a way that itsoperating portion remains in precisely the same position.

The drawings and the foregoing specification constitute a description ofthe improved grinder with compensating trimming mechanism in such full,clear, concise and exact terms as to'enable any person skilled in theart to practice the invention, the scope of which is indicated by theappended claims.

What we claim as our invention is:

1. A grinder comprising a frame, a grinding wheel support movable onsaid frame toward and away from the path of movement of a work piece, acompound screw mounted on said movable support for rotation butprevented from endwise movement relative to said support, an adjustmentnut carried by said frame for rotation but prevented from endwisemovement relative thereto, and threadedly engaged with a first portionof said screw, a wheel trimmer device mounted on said wheel support formovement parallel to the axis of said screw, a nut fixedly carried bysaid device and threadedly engaged with a second portion of said screw,said portions of said screw having threads of opposite hand, and meansfor selectively rotating said adjustment nut and said screw.

' 2. A grinder comprising a frame, a grinding wheel support movable onsaid frame toward and away from the path of movement of a work piece, acompound screw mounted on said movable support for rotation butprevented from endwise movement relative to said support, an adjustmentnut carried by said frame for rotation but prevented from endwisemovement relative thereto, and

threadedly engaged with a first portion of said screw, a wheel trimmerdevice mounted on said wheel support for movement parallel to the axis'of said screw, a nut fixedly carried by said device and threadedlyengaged with a second portion of said screw, said portions of said screwhaving threads of opposite hand, and drive means for selectivelyrotating said adjustment nut and said screw, said means beingirreversible to selectively lock said. adjustment nut and screw againstrotation except when operated by said drive means.

3. A grinder comprising a frame, a grinding wheel support movable onsaid frame toward and away from the path of movement of a work piece, acompound screw mounted on said movable support for rotation butprevented from endwise movement relative to said support,

an adjustment nut carried by said frame for rotation but prevented fromendwise movement relative thereto, and threadedly engaged with a firstportion of'said screw, a Wheel trimmer device mounted on said wheelsupport for movement parallel to the axis of said screw, a nut fixedlycarried by said deviceiand threadedly engaged with a second portion ofsaid screw, said portions of said screw having threads of opposite hand,and means for selectively rotating said adjustment nut and said screw,said means comprising irreversible worm and worm gear means. j

4. A grinder comprising a frame, a grinding wheel support movable onsaid frame toward and away from the path of movement of a work piece, aplate on said wheel support on which is mounted a grinding wheel anddrive means therefor, and means for adjusting said plate in a directionperpendicularto the direction of movement of said wheel support, acompound screw mounted on said movable support for rotation butprevented from endwise movement relative to said support, an adjustmentnut carried by said frame for rotation but prevented from endwisemovement relative thereto, and threadedly engaged with a first portionof said screw, a

wheel trimmer device mounted on said wheel support for movement parallelto the axis of said screw, a nut fixedly carried by said device andthreadedly engaged with a second portion of said screw, said portions ofsaid screw having threads of opposite hand, first drive means forrotating said adjustment nut, and second drive means for rotating saidscrew. I

5. A grinder comprising a frame, a column movable on said frame, a wheeltrimmer movable longitudinally on said column, a plate on said columnmovable thereon transversely of said column,,a grinding wheel and drivemeans therefor on said plate, means for effecting equal increments ofadjustment of said column on said frame and of said trimmer on saidcolumn, said last means comprising a screw carried by said column, afirst nut threaded on said screw and fixed to said frame and a secondnut threaded to said screw and fixed toySaid trimmer, and selectivelyoperable drive means for said screw and for said first nut.

6. A grinder comprising a frame, a column movable on said frame, a wheeltrimmer movable longitudinally on said column, a plate on said columnmovable thereon transversely of said column, a grinding wheel and drivemeans therefor on said plate, means for eifeoting equal increments ofadjustment of said column on saidframe and of said trimmer on saidcolumn, said last means comprising a screw carried by said column, afirst nut threaded on said screw and fixed to said frame and a secondnut threaded to said screw and fixed to said trimmer, and selectivelyoperable drive means for said screw and for said first nut, said drivemeans being irreversible to lock said screw and first nut againstrotation except when actuated by said drive means.

References Cited in the file of this patent UNITED STATES PATENTSBabbitt Sept, 9,' 1958

